Dermal cysts
Dermal cysts are common in dermatopathology. Dermatopathologists can diagnose 'em.
Cysts
Common types:[1]
- Epidermal cyst (sebaceous cyst) -- most common.
- Pilar (tricheilemmal) cyst.
- Dermoid cyst.
- Ganglion cyst.
- Milicem.
EM, SJS, TEN
- SJS and TEN are on a spectrum, EM is considered separate.
Erythema multiforme
- Abbreviated EM.
General
Features:[2]
- Hypersensitivity disorder to a drug or infections.
- Assoc. with the following: HSV, Mycoplasma, Histoplasma, others.
Clinical:
- Target-like lesion.
Microscopic
Features:[2]
- Lymphocytic interface dermatitis (lymphocytes at the dermal-epidermal junction).
- Necrotic/degenerative keratinocytes - key feature.
- +/-Epidermal blistering.
- +/-Epidermal sloughing.
Stevens-Johnson Syndrome
- Abbreviated SJS.
Rx causes of SJS:
- NSAIDs.
- Anticonvulsants.
- Sulfonamides.
- Penicillins.
Toxic Epidermal Necrolysis
- Abbreviated TEN.
TEN more severe form SJS.
Definition:
- >30% sheet-like epidermal detachment, diffuse erythema, severe mucous membrane involvement.
- Most TEN (80%) Rx-related, only 50% of SJS Rx-related.
Venous lake
- Dilated vein.
Microscopic
Features:[3]
- Lined by endothelium.
- Blood in lumen.
- +/-Fibrin in lumen.
DDx:
- Angiokeratoma.
- Ectatic superficial dermal vessels.
- Irregular acanthosis.
- Longer rete ridges.
Neurofibromatosis (von Recklinghausen's disease)
Main article: Neurofibromatosis
Etiology
- Genetic - autosomal dominant disorder.
Management
- Follow for malignant transformation of neurofibroma --> neurofibrosarcoma.
Treatment
- Excise suspicious lesions & lesions that are painful.
Collagenous fibroma
General
- Benign.
- Used to be known as desmoplastic fibroblastoma.
Epidemiology:
- May be on the lip.
Microscopic
- Acellular stroma with abundant collagen.
Notes:
- No nuclear atypia.
Dermatomyositis
Gross
- Have lesions on the knuckle - Gottron's papulle
Histology
- Lymphocytic interface dermatitis (inflammation at the dermal-epidermal junction).
- Loss of rete ridges.
Systemic lupus erythematosus
Familial benign pemphigus
- AKA Hailey-Hailey disease. Was described by two brothers - that's why it is Hailey-Hailey.[8]
Etiology
- Autosomal dominant with incomplete penetration.[8]
- Desmosomal defect - due to mutation in the gene ATP2C1.[8]
Clinical
- Chest.
- Intriginous regions (?sp).
- Typically presents individual in their 30s and 40s.[8]
Histology
- Hair folicles spared.
- Epidermis thickened.
DDx
- May resemble pemphigus vulgaris.
Epidermal inclusion cyst
- AKA epidermal cyst.
General
- Very common.
Microscopic
Feature:
- Cyst lining has a granular layer - key feature.[9]
- Trapped collagen bundles at edge of lesion with surrounded by fibroblasts.
- Keratin.
Image:
DDx:
- Dermatofibrosarcoma - if lesion is large.
- Pilar cyst - no granular layer.
See also
References
- ↑ TN07 D5
- ↑ 2.0 2.1 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1189. ISBN 978-1416031215.
- ↑ Weedon's Skin Pathology. 3rd Ed. P.895.
- ↑ URL: http://www.dermatologyoutlines.com/dermskintumornonmelanocytic.html#collagenousfibroma. Accessed on: 19 March
- ↑ Mills, Stacey E; Carter, Darryl; Greenson, Joel K; Oberman, Harold A; Reuter, Victor E (2004). Sternberg's Diagnostic Surgical Pathology (4th ed.). Lippincott Williams & Wilkins. pp. 161. ISBN 978-0781740517.
- ↑ JAH. 20 February 2009.
- ↑ Crowson AN, Magro CM, Mihm MC (April 2008). "Interface dermatitis". Arch. Pathol. Lab. Med. 132 (4): 652–66. PMID 18384217. http://www.archivesofpathology.org/doi/full/10.1043/1543-2165%282008%29132%5B652%3AID%5D2.0.CO%3B2.
- ↑ 8.0 8.1 8.2 8.3 http://emedicine.medscape.com/article/1063224-overview
- ↑ URL: http://emedicine.medscape.com/article/1058907-diagnosis. Accessed on: 18 March 2011.